BMJ Open Respir Res. 2024 Jun 4;11(1):e002148. doi: 10.1136/bmjresp-2023-002148.

ABSTRACT

OBJECTIVE: This study aims to explore the common genetic basis between respiratory diseases and to identify shared molecular and biological mechanisms.

METHODS: This genome-wide pleiotropic association study uses multiple statistical methods to systematically analyse the shared genetic basis between five respiratory diseases (asthma, chronic obstructive pulmonary disease, idiopathic pulmonary fibrosis, lung cancer and snoring) using the largest publicly available genome wide association studies summary statistics. The missions of this study are to evaluate global and local genetic correlations, to identify pleiotropic loci, to elucidate biological pathways at the multiomics level and to explore causal relationships between respiratory diseases. Data were collected from 27 November 2022 to 30 March 2023 and analysed from 14 April 2023 to 13 July 2023.

MAIN OUTCOMES AND MEASURES: The primary outcomes are shared genetic loci, pleiotropic genes, biological pathways and estimates of genetic correlations and causal effects.

RESULTS: Significant genetic correlations were found for 10 paired traits in 5 respiratory diseases. Cross-Phenotype Association identified 12 400 significant potential pleiotropic single-nucleotide polymorphism at 156 independent pleiotropic loci. In addition, multitrait colocalisation analysis identified 15 colocalised loci and a subset of colocalised traits. Gene-based analyses identified 432 potential pleiotropic genes and were further validated at the transcriptome and protein levels. Both pathway enrichment and single-cell enrichment analyses supported the role of the immune system in respiratory diseases. Additionally, five pairs of respiratory diseases have a causal relationship.

CONCLUSIONS AND RELEVANCE: This study reveals the common genetic basis and pleiotropic genes among respiratory diseases. It provides strong evidence for further therapeutic strategies and risk prediction for the phenomenon of respiratory disease comorbidity.

PMID:38834332 | DOI:10.1136/bmjresp-2023-002148

Expert Opin Pharmacother. 2024 Jun 4:1-9. doi: 10.1080/14656566.2024.2354460. Online ahead of print.

ABSTRACT

INTRODUCTION: Following the INPULSIS and ASCEND studies, leading to the first two approved antifibrotic therapies for patients with IPF, ongoing investigations are firmly exploring novel agents for a targeted effective and better tolerated therapy able to improve the natural history of the disease.

AREAS COVERED: This review aims to analyze recent advances in pharmacological research of IPF, discussing the currently available treatments and the novel drugs under investigation in phase 3 trials, with particular emphasis on BI 1015550 and inhaled treprostinil. The literature search utilized Medline and Clinicaltrials.org databases. Critical aspects of clinical trial design in IPF are discussed in light of recently completed phase III studies.

EXPERT OPINION: While randomized clinical trials in IPF are currently underway, future objectives should explore potential synergistic benefits when combining novel molecules with the existing therapies and identify more specific molecular targets. Moreover, refining the study design represent another crucial goal. The aim of the pharmacological research will be not only stabilizing but also potentially reversing the fibrotic changes in IPF.

PMID:38832823 | DOI:10.1080/14656566.2024.2354460

Aging Cell. 2024 Jun 3:e14229. doi: 10.1111/acel.14229. Online ahead of print.

ABSTRACT

Idiopathic pulmonary fibrosis is a progressive and age-related disease that results from impaired lung repair following injury. Targeting senescent myofibroblasts with senolytic drugs attenuates pulmonary fibrosis, revealing a detrimental role of these cells in pulmonary fibrosis. The mechanisms underlying the occurrence and persistence of senescent myofibroblasts in fibrotic lung tissue require further clarification. In this study, we demonstrated that senescent myofibroblasts are resistant to apoptosis by upregulating the proapoptotic protein BAX and antiapoptotic protein BCL-2 and BCL-XL, leading to BAX inactivation. We further showed that high levels of inactive BAX-mediated minority mitochondrial outer membrane permeabilization (minority MOMP) promoted DNA damage and myofibroblasts senescence after insult by a sublethal stimulus. Intervention of minority MOMP via the inhibition of caspase activity by quinolyl-valyl-O-methylaspartyl-[2,6-difluorophenoxy]-methyl ketone (QVD-OPH) or BAX knockdown significantly reduced DNA damage and ultimately delayed the progression of senescence. Moreover, the BAX activator BTSA1 selectively promoted the apoptosis of senescent myofibroblasts, as BTSA1-activated BAX converted minority MOMP to complete MOMP while not injuring other cells with low levels of BAX. Furthermore, therapeutic activation of BAX with BTSA1 effectively reduced the number of senescent myofibroblasts in the lung tissue and alleviated both reversible and irreversible pulmonary fibrosis. These findings advance the understanding of apoptosis resistance and cellular senescence mechanisms in senescent myofibroblasts in pulmonary fibrosis and demonstrate a novel senolytic drug for pulmonary fibrosis treatment.

PMID:38831635 | DOI:10.1111/acel.14229

bioRxiv [Preprint]. 2024 May 23:2024.05.21.595153. doi: 10.1101/2024.05.21.595153.

ABSTRACT

Fibrosis drives end-organ damage in many diseases. However, clinical trials targeting individual upstream activators of fibroblasts, such as TGFβ, have largely failed. Here, we target the leukemia inhibitory factor receptor (LIFR) as a "master amplifier" of multiple upstream activators of lung fibroblasts. In idiopathic pulmonary fibrosis (IPF), the most common fibrotic lung disease, we found that lung myofibroblasts had high LIF expression. Further, TGFβ1, one of the key drivers of fibrosis, upregulated LIF expression in IPF fibroblasts. In vitro anti-LIFR antibody blocking on human IPF lung fibroblasts reduced induction of profibrotic genes downstream of TGFβ1, IL-4 and IL-13. Further, siRNA silencing of LIFR in IPF precision cut lung slices reduced expression of fibrotic proteins. Together, we find that LIFR drives an autocrine positive feedback loop that amplifies and sustains pathogenic activation of IPF fibroblasts downstream of multiple external stimuli, implicating LIFR as a therapeutic target in fibrosis.

SIGNIFICANCE STATEMENT: Fibroblasts have a central role in the pathogenesis of fibrotic diseases. However, due to in part to multiple profibrotic stimuli, targeting a single activator of fibroblasts, like TGFβ, has not yielded successful clinical treatments. We hypothesized that a more effective therapeutic strategy is identifying a downstream "master amplifier" of a range of upstream profibrotic stimuli. This study identifies the leukemia inhibitory factor receptor (LIFR) on fibrotic lung fibroblasts amplifies multiple profibrotic stimuli, such as IL-13 and TGFβ. Blocking LIFR reduced fibrosis in ex vivo lung tissue from patients with idiopathic pulmonary fibrosis (IPF). LIFR, acting as a master amplifier downstream of fibroblast activation, offers an alternative therapeutic strategy for fibrotic diseases.

PMID:38826450 | PMC:PMC11142130 | DOI:10.1101/2024.05.21.595153

Respirology. 2024 Jun 2. doi: 10.1111/resp.14763. Online ahead of print.

ABSTRACT

BACKGROUND AND OBJECTIVE: Evidence for the benefit of steroid therapy in acute exacerbations (AEs) of idiopathic pulmonary fibrosis (IPF) is limited; however, they remain a cornerstone of management in other fibrotic interstitial lung diseases. This retrospective observational study assesses the effect of steroid treatment on in-hospital mortality in patients with acute exacerbation of fibrotic interstitial lung disease (AE-FILD) including IPF and non-IPF ILDs.

METHODS: AE-FILD cases over a 10-year period were filtered using a code-based algorithm followed by individual case evaluation. Binary logistic regression analysis was used to assess the relationship between corticosteroid treatment (defined as ≥0.5 mg/kg/day of prednisolone-equivalent for ≥3 days within the first 72 h of admission) and in-hospital mortality or need for lung transplantation. Secondary outcomes included readmission, overall survival, requirement for domiciliary oxygen and rehabilitation.

RESULTS: Across two centres a total of 107 AE-FILD subjects were included, of which 46 patients (43%) received acute steroid treatment. The steroid cohort was of younger age with fewer comorbidities but had higher oxygen requirements. Pre-admission FVC and DLCO, distribution of diagnoses and smoking history were similar. The mean steroid treatment dose was 4.59 mg/kg/day. Steroid use appeared to be associated with increased risk of inpatient mortality or transplantation (OR 4.11; 95% CI 1.00-16.83; p = 0.049). In the steroid group, there appeared to be a reduced risk of all-cause mortality in non-IPF patients (HR 0.21; 95% CI 0.04-0.96; p = 0.04) compared to their IPF counterparts. Median survival was reduced in the steroid group (221 vs. 520.5 days) with increased risk of all-cause mortality (HR 3.25; 95% CI 1.56-6.77; p < 0.01).

CONCLUSION: In this two-centre retrospective study of 107 patients, AE-FILD demonstrates a high risk of mortality, at a level similar to that seen for AE-IPF, despite steroid treatment. Clinicians should consider other precipitating factors for exacerbations and use steroids judiciously. Further prospective trials are needed to determine the role of corticosteroids in AE-FILD.

PMID:38825348 | DOI:10.1111/resp.14763

Am J Respir Crit Care Med. 2024 May 31. doi: 10.1164/rccm.202402-0337LE. Online ahead of print.

NO ABSTRACT

PMID:38820300 | DOI:10.1164/rccm.202402-0337LE

Am J Respir Crit Care Med. 2024 May 31. doi: 10.1164/rccm.202404-0789LE. Online ahead of print.

NO ABSTRACT

PMID:38820297 | DOI:10.1164/rccm.202404-0789LE

Am J Respir Cell Mol Biol. 2024 May 31. doi: 10.1165/rcmb.2024-0124PS. Online ahead of print.

ABSTRACT

Pulmonary fibrosis (PF) can be idiopathic or driven by a specific insult or disease process. Inflammation plays a role in the pathophysiology, the extent of which remains a longstanding topic of debate. More recently there has been increasing interest in a potential inciting role for aberrant lipid metabolism. Lipids are essential for the structure and function of all cell membranes but specifically in the lung for surfactant composition, intra and intercellular lipid mediators and lipofibroblasts. Clinically, there is evidence of increased lipid deposition in the subpleural space, and at a whole lung tissue level in PF. There is evidence of increased parenchymal lipid deposition and abnormal mediastinal fat shape on chest CT. A protective role for cholesterol lowering drugs including statins and ezetimibe has been described in PF. At a cellular level, fatty acid (FA), phospholipid (PL) and glucose metabolism are disordered, as is the production of lipid mediators. In this perspectives piece we put forward the argument that there is substantive clinical and biological evidence to support a role for aberrant lipid metabolism and lipid mediators in the pathogenesis of PF.

PMID:38820234 | DOI:10.1165/rcmb.2024-0124PS

J Cancer. 2024 Apr 29;15(11):3406-3417. doi: 10.7150/jca.95437. eCollection 2024.

ABSTRACT

Background: Pulmonary diseases and esophageal cancer are highly prevalent conditions with rising incidence worldwide. Prior evidence supports shared environmental and behavioral factors, but less is known regarding potential genetic links underlying this comorbidity. This study aimed to elucidate the complex genetic relationship between chronic lung diseases and esophageal cancer risk. Methods: Linkage disequilibrium score regression assessed the genetic correlation between esophageal cancer and asthma, COPD, and idiopathic pulmonary fibrosis leveraging extensive GWAS datasets. Pleiotropic analysis, gene-set enrichment, eQTL mapping, and mendelian randomization causality analyses were then conducted to identify specific shared genetic variants, enriched pathways, causal relationships and gene regulatory mechanisms connecting lung disease and cancer susceptibility. Results: Significant genetic correlations were observed between esophageal cancer and both COPD and asthma, but not idiopathic pulmonary fibrosis. Further analyses identified 13 pleiotropic loci and 6 shared genes including CHRNA4, ERBB3, and SMAD3, as well as pathways related to immune function. eQTL integration highlighted 53 genes like SOCS1, FGF2, and CHRNA5 with tissue-specific regulatory effects on disease risk. Bidirectional relationships were noted, whereby genetic predisposition to asthma and COPD increased esophageal cancer risk, while cancer liability reciprocally raised pulmonary fibrosis risk. Conclusions: These genomic analyses provide initial evidence that shared genetic factors may underpin the comorbidity between lung conditions and esophageal malignancy. The genes and pathways identified offer insights into biological mechanisms linking both diseases, aiding future screening, prevention and therapeutic efforts to mitigate this growing comorbidity burden.

PMID:38817868 | PMC:PMC11134432 | DOI:10.7150/jca.95437

Cureus. 2024 Apr 29;16(4):e59323. doi: 10.7759/cureus.59323. eCollection 2024 Apr.

ABSTRACT

Aspergilloma also known as fungal ball or mycetoma, is a saprophytic mycotic infection caused by Aspergillus species which usually colonizes pre-existing cavitary or cystic lesions in the lung. Here, we have a rare case of idiopathic pulmonary fibrosis (IPF) with bilateral bronchiectasis complicated by aspergilloma. Although the existence of aspergilloma is common in pre-existing lung cavities, its coexistence in patients with IPF is a rarity, and the incidence of such cases in the literature remains sparse. Here is an interesting case report of aspergilloma co-existing with IPF. This article comprehensively analyzes the existing literature depicting similar associations and the possible etiology for the development of aspergilloma in patients with IPF.

PMID:38817531 | PMC:PMC11137344 | DOI:10.7759/cureus.59323

Clin Chest Med. 2024 Jun;45(2):419-431. doi: 10.1016/j.ccm.2023.08.015. Epub 2023 Sep 15.

ABSTRACT

The American Thoracic Society/European Respiratory Society/Japanese Respiratory Society/Asociación Latinoamericana de Tórax 2018 clinical practice guideline and 2022 update provide recommendations to define and diagnose idiopathic pulmonary fibrosis (IPF) in patients with newly diagnosed interstitial lung disease. The guideline emphasizes recognition of usual interstitial pneumonia (UIP) and probable UIP patterns of fibrosis on high-resolution CT, which can obviate the need for surgical lung biopsy and allow timely initiation of antifibrotic pharmacotherapy citing a high correlation with UIP on histopathology. This article reviews the recent 2022 IPF clinical practice guideline with a focus on the imaging updates.

PMID:38816097 | DOI:10.1016/j.ccm.2023.08.015

BMJ Open. 2024 May 30;14(5):e081103. doi: 10.1136/bmjopen-2023-081103.

ABSTRACT

BACKGROUND: 18Fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) CT imaging has been used in many inflammatory and infectious conditions to differentiate areas of increased metabolic activity. FDG uptake differs between areas of normal lung parenchyma and interstitial lung disease (ILD).

OBJECTIVES: In this study, we investigated whether FDG-PET/CT parameters were associated with a change in the quality of life (QoL) in patients with ILD over 4 years of follow-up.

METHODS: Patients underwent PET-CT imaging at diagnosis and were followed up with annual QoL assessment using the St George's Respiratory Questionnaire (SGRQ) until death or 4 years of follow-up. Maximum standard uptake value (SUVmax) and Tissue-to-Background Ratio (TBR) were assessed against SGRQ overall and subscale scores.

RESULTS: 193 patients (94 patients in the idiopathic pulmonary fibrosis (IPF) subgroup and 99 patients in the non-IPF subgroup) underwent baseline FDG-PET/CT imaging and QoL assessment. Weak-to-moderate correlation was observed between baseline SUVmax and SGRQ scores in both ILD subgroups. No relationship was observed between baseline SUVmax or TBR and change in SGRQ scores over 4 years of follow-up. In the IPF subgroup, surviving patients reported a decline in QoL at 4 years post diagnosis whereas an improvement in QoL was seen in surviving patients with non-IPF ILD.

CONCLUSIONS: Weak-to-moderate positive correlation between baseline SUVmax and SGRQ scores was observed in both ILD subgroups (IPF:rs=0.187, p=0.047, non-IPF: rs=0.320, p=0.001). However, baseline SUVmax and TBR were not associated with change in QoL in patients with IPF and non-IPF ILD over 4 years of follow-up. At 4 years post diagnosis, surviving patients with IPF reported declining QoL whereas improvement was seen in patients with ILD who did not have IPF.

PMID:38816048 | DOI:10.1136/bmjopen-2023-081103

Eur Respir J. 2024 May 30;63(5):2400760. doi: 10.1183/13993003.00760-2024. Print 2024 May.

NO ABSTRACT

PMID:38816038 | DOI:10.1183/13993003.00760-2024

Respir Investig. 2024 May 29;62(4):702-709. doi: 10.1016/j.resinv.2024.05.005. Online ahead of print.

ABSTRACT

BACKGROUND: Interstitial lung diseases (ILDs) are a heterogeneous group of disorders, a subset of which develop progressive pulmonary fibrosis (PPF). There is little information on the epidemiology and treatment of PPFs in Japan. This retrospective cohort study estimated the incidence probability of progression to PPFs in patients with fibrosing ILDs other than idiopathic pulmonary fibrosis in a real-world Japanese setting. Management procedures and treatment patterns were also quantified.

METHODS: Data were extracted from the Medical Data Vision database from 01-Jan-2012 to 28-May-2020, comprising a 6.91-year patient identification period, 1-year pre-index period, and post-index period. The primary outcome was the cumulative incidence probability of progression to PPF up to 24 months. Subgroup analyses were performed by the presence/absence of connective tissue disease-ILD and by pre-specified ILD clinical diagnosis.

RESULTS: Of the 34,960 eligible patients (mean age: 71.1 years, males: 52.5%), 14,580 (41.7%) progressed to PPF. The 24-month incidence probability of progression to PPF was 39.5%. A relatively comparable percentage of patients progressed across all ILD subtypes. Oral corticosteroids and tacrolimus were the most common therapies during the pre- and post-index periods. Treatment rates were very low in the post-index period.

CONCLUSIONS: This is the first claims database study to estimate the incidence probability of progression to PPF in Japan. Progression appeared common in patients with chronic fibrosing ILDs, with comparable percentages of patients across all subtypes developing PPF at 2 years. Future studies should assess the impact of regular monitoring and early intervention on treating fibrotic ILDs and preventing progression.

PMID:38815414 | DOI:10.1016/j.resinv.2024.05.005

Respir Care. 2024 May 28;69(6):697-712. doi: 10.4187/respcare.12089.

ABSTRACT

Over the last 3 decades, pulmonary rehabilitation (PR) has become an integral part of the management of COPD. Many other chronic respiratory diseases have similar systemic manifestations including skeletal muscle impairment, commonly through deconditioning, and may benefit from PR. However, whereas many programs may accept patients with other respiratory diseases, the program may need several adaptations to optimally manage patients. This article uses the examples of interstitial lung disease including idiopathic pulmonary fibrosis, bronchiectasis, pulmonary hypertension, post lung transplantation, and post-COVID condition to highlight exemplar clinical problems. In addition, the rationale and latest evidence for PR are described alongside the adaptations to the program, including education needs of the delivery team and close integrated care with the wider clinical team. Finally, future directions for clinical care and research are discussed.

PMID:38806225 | DOI:10.4187/respcare.12089

Bioorg Chem. 2024 May 18;149:107474. doi: 10.1016/j.bioorg.2024.107474. Online ahead of print.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, and high mortality lung disease. Although the antifibrotic drugs pirfenidone and nintedanib could slow the rate of lung function decline, the usual course of the condition is inexorably to respiratory failure and death. Therefore, new approaches and novel therapeutic drugs for the treatment of IPF are urgently needed. And the selective PDE4 inhibitor has in vivo and in vitro anti-fibrotic effects in IPF models. But the clinical application of most PDE4 inhibitors are limited by their unexpected and severe side effects such as nausea, vomiting, and diarrhea. Herein, structure-based optimizations of the natural product Moracin M resulted in a novel a novel series of 2-arylbenzofurans as potent PDE4 inhibitors. The most potent inhibitor L13 has an IC50 of 36 ± 7 nM with remarkable selectivity across the PDE families and administration of L13·citrate (10.0 mg/kg) exhibited comparable anti-pulmonary fibrosis effects to pirfenidone (300 mg/kg) in a bleomycin-induced IPF mice model, indicate that L13 is a potential lead for the treatment of IPF.

PMID:38805909 | DOI:10.1016/j.bioorg.2024.107474

Respirology. 2024 May 28. doi: 10.1111/resp.14757. Online ahead of print.

NO ABSTRACT

PMID:38803315 | DOI:10.1111/resp.14757

Drug Des Devel Ther. 2024 May 22;18:1711-1725. doi: 10.2147/DDDT.S464485. eCollection 2024.

ABSTRACT

Imrecoxib, a cyclooxygenase-2 (COX-2) selective non-steroidal anti-inflammatory drug (NSAID), was discovered via the balanced inhibition strategy of COX-1/COX-2. It is indicated for the relief of painful symptoms of osteoarthritis. There have been some pharmacological and therapeutic advances since the approval of imrecoxib in 2011. However, an update review in this aspect is not yet available. Relevant literature until January 2024 was identified by search of PubMed, Web of science, Embase and CNKI. From the perspective of efficacy, imrecoxib provides relief of osteoarthritis symptoms, and potential off-label use for treatment of idiopathic pulmonary fibrosis, perioperative pain, hand-foot syndrome, axial spondyloarthritis, COVID-19, cartilage injury, and malignancies such as lung and colon cancer. From a safety point of view, imrecoxib showed adverse effects common to NSAIDs; however, it has lower incidence of new-onset hypertension than other types of selective COX-2 inhibitors, less gastrointestinal toxicities than non-selective NSAIDs, weaker risk of drug interaction than celecoxib, and more suitable for elderly patients due to balanced inhibition of COX-1/COX-2. From a pharmacoeconomic perspective, imrecoxib is more cost-effective than celecoxib and diclofenac for osteoarthritis patients. With the deepening of the disease pathophysiology study of osteoarthritis, new therapeutic schemes and pharmacological mechanisms are constantly discovered. In the field of osteoarthritis treatment, mechanisms other than the analgesic and anti-inflammatory effects of COX-2 inhibitors are also being explored. Taken together, imrecoxib is a moderate selective COX-2 inhibitor with some advantages, and there would be more clinical applications and research opportunities in the future.

PMID:38799798 | PMC:PMC11128231 | DOI:10.2147/DDDT.S464485

Regen Ther. 2024 May 17;26:27-32. doi: 10.1016/j.reth.2024.05.002. eCollection 2024 Jun.

ABSTRACT

OBJECTIVE: We aimed to examine whether heparin-binding epidermal growth factor-like growth factor (HB-EGF) affects the lung fibrosis process through the activation of p38 protein in mitogen-activated protein kinases (MAPK) signaling pathway, as well as the expression of downstream inflammatory factors.

METHODS: The expression levels of HB-EGF, collagen type I (COL-I), and hexokinase 2 (HK2) in peripheral blood mononuclear cells (PBMCs) of patients with connective tissue disease-related interstitial lung disease (CTD-ILD) were examined by qPCR, Western blotting and ELISA.

RESULTS: In vitro experiments showed that HB-EGF was increased in almost all subtypes [rheumatoid arthritis (RA), systemic sclerosis (SSc) and idiopathic inflammatory myopathies (IIMs)] as well as in all groups (P < 0.05). For embryonic lung fibroblast (A549) cells, the expression levels of HK2 and α-smooth muscle actin (α-SMA) genes were elevated during 0-4 h and then plateaued. Transforming growth factor-β1 (TGF-β1) induced fibrosis in human embryonic lung fibroblasts (MRC-5) cells and A549 for a certain period of time, but the degree of induction varied, which may be related to the redifferentiability of cells at different spatial locations. Moreover, HB-EGF at concentrations above 1 ng/ml stimulation increased COL-I expression (P < 0.05), and for α-SMA gene, even 1 ng/ml concentration of HB-EGF had a stimulatory effect, and different concentrations of HB-EGF did activate the expression of p38 in a concentration-dependent manner within a certain concentration range, and by The qPCR results showed that for interleukin 6 (IL-6), an inflammatory factor regulated downstream of p38, the expression was significantly increased in A549 cells compared to control (P < 0.05), but tumor necrosis factor-α (TNF-α) expression was downregulated (P < 0.05), but for interleukin-1β (IL-1β) gene, there was no significant difference in A549 cells, and expression was downregulated in MRC-5 cells. Therefore, it is suggested that HB-EGF regulates the expression of inflammatory factors through p38 will be differential across cells.

CONCLUSION: Our study shows that HB-EGF can suppress pulmonary fibrosis through downstream activation of p38/MAPK pathway activity, as well as the expression of various inflammatory factors downstream of it.

PMID:38798743 | PMC:PMC11127469 | DOI:10.1016/j.reth.2024.05.002

Pharmacol Ther. 2024 May 23:108669. doi: 10.1016/j.pharmthera.2024.108669. Online ahead of print.

ABSTRACT

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal disease for which therapeutic options are limited, with an unmet need to identify new therapeutic targets. IPF is thought to be the consequence of repeated microlesions of the alveolar epithelium, leading to aberrant epithelial-mesenchymal communication and the accumulation of extracellular matrix proteins. The reactivation of developmental pathways, such as Fibroblast Growth Factors (FGFs), is a well-described mechanism during lung fibrogenesis. Secreted FGFs with local paracrine effects can either exert an anti-fibrotic or a pro-fibrotic action during this pathological process through their FGF receptors (FGFRs) and heparan sulfate residues as co-receptors. Among FGFs, endocrine FGFs (FGF29, FGF21, and FGF23) play a central role in the control of metabolism and tissue homeostasis. They are characterized by a low affinity for heparan sulfate, present in the cell vicinity, allowing them to have endocrine activity. Nevertheless, their interaction with FGFRs requires the presence of mandatory co-receptors, alpha and beta Klotho proteins (KLA and KLB). Endocrine FGFs are of growing interest for their anti-fibrotic action during liver, kidney, or myocardial fibrosis. Innovative therapies based on FGF19 or FGF21 analogs are currently being studied in humans during liver fibrosis. Recent data report a similar anti-fibrotic action of endocrine FGFs in the lung, suggesting a systemic regulation of the pulmonary fibrotic process. In this review, we summarize the current knowledge on the protective effect of endocrine FGFs during the fibrotic processes, with a focus on pulmonary fibrosis.

PMID:38795981 | DOI:10.1016/j.pharmthera.2024.108669